The conventional industrial method for preparing 2,4,5-trichlorophenol involves the reaction of 1,2,4,5-tetrachlorobenzene with methyl alcoholic or aqueous methyl alcoholic sodium hydroxide. The crude product which is available commercially is about 94% 2,4,5-trichlorophenol and about six percent impurities which are primarily dichlorophenols and dichloromethoxyphenols.
The germacide known as Hexachlorophene.RTM. (bis-[3,5,6-trichloro-2-hydroxyphenyl]methane), is prepared by condensing 2,4,5-trichlorophenol with formaldehyde. In order to get a germicide of high purity, it is desirable to start with a 2,4,5-trichlorophenol of high purity. Since the dichlorophenols and dichloromethoxyphenols present in the commercial grade 2,4,5-trichlorophenol will also react with formaldehyde, it is desirable to remove them prior to the condensation.